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Viewing 241 to 270 of 16221
2015-04-14
Technical Paper
2015-01-1443
Morteza Seidi, Marzieh Hajiaghamemar, James Ferguson, Vincent Caccese
Abstract Falls in the elderly population is an important concern to individuals and in the healthcare industry. When the head is left unprotected, head impact levels can reach upwards of 500 g (gravitational acceleration), which is a level that can cause serious injury or death. A protective system for a fall injury needs to be designed with specific criteria in mind including energy protection level, thickness, stiffness, and weight among others. The current study quantifies the performance of a protective head gear design for persons prone to falls. The main objective of this paper is to evaluate the injury mitigation of head protection gear made from a patented system of polyurethane honeycomb and dilatant materials. To that end, a twin wire fall system equipped with a drop arm that includes a Hybrid-III head/neck assembly was used. The head was instrumented with an accelerometer array.
2015-04-14
Technical Paper
2015-01-1448
Lee Carr, Robert Rucoba, Dan Barnes, Steven Kent, Aaron Osterhout
Abstract With commercial availability of the Bosch Crash Data Retrieval Tool (CDR), the information stored in vehicle Event Data Recorders (EDRs) has increasingly been used to supplement traditional traffic crash data collection and reconstruction methods, allowing enhanced confidence levels in transportation safety research. The objective of this study was to assess the accuracy and reliability of EDR data images obtained with the Bosch CDR tool by comparing them to a known crash impulse. Multiple EDRs and necessary sensor arrays were mounted on a HYGE™ acceleration-type crash simulation sled system at various orientations representing different principal direction of force (PDOF) angles and subjected to controlled “crash” impulses, simulating a “deployment event” (DE) and triggering data to be saved in the EDRs. The data included in each EDR's CDR report was compared to the known conditions of the impulse.
2015-04-14
Technical Paper
2015-01-1451
Anand Sai Gudlur, Theresa Atkinson
Abstract The current study examined field data in order to document injury rates, injured body regions, and injury sources for persons seated in the second row of passenger vehicles. It was also intended to identify whether these varied with respect to age and restraint use in vehicles manufactured in recent years. Data from the 2007-2012 National Automotive Sampling System (NASS/CDS) was used to describe occupants seated in the second row of vehicles in frontal crashes. Injury plots, comparison of means and logistic regression analysis were used to seek factors associated with increased risk of injury. Restraint use reduced the risk of AIS ≥ 2 injury from approximately 1.8% to 5.8% overall. Seventy nine percent of the occupants in the weighted data set used either a lap and shoulder belt or child restraint system. The most frequently indicated injury source for persons with a MAIS ≥ 2 was “seat, back support”, across restraint conditions and for all but the youngest occupants.
2015-04-14
Technical Paper
2015-01-1452
Kathleen DeSantis Klinich, Kyle Boyle, Laura Malik, Miriam Manary, Jingwen Hu
This study documented the position and orientation of child restraint systems (CRS) installed in the second rows of vehicles, creating a database of 486 installations. Thirty-one different CRS were evaluated, selected to provide a range of manufacturers, sizes, types, and weight limits. Eleven CRS were rear-facing only, fourteen were convertibles, five were combination restraints, and one was a booster. Ten top-selling vehicles were selected to provide a range of manufacturers and body styles: four sedans, four SUVS, one minivan, and one wagon. CRS were marked with three reference points on each moving component. The contours and landmarks of each CRS were first measured in the laboratory. Vehicle interior contours, belt anchors, and LATCH anchors were measured using a similar process. Then each CRS was installed in a vehicle using LATCH according to manufacturers' directions, and the reference points of each CRS component were measured to document the installed orientation.
2015-04-14
Technical Paper
2015-01-1456
Mani Ayyakannu, Latha Subbiah, Mohammed Syed
Abstract Automotive knee bolster requirements have changed substantially in recent years due to expanded safety requirements. A three-piece cellular structural knee bolster assembly has been evolved to meet this matrix of requirements while being extremely lightweight (as low as 0.7 Kg), low in cost and easily tunable to work in various car/truck programs. The energy absorber is the primary component of this assembly and allows for a range of occupant sizes and weights to be restrained (from 50 Kg/152 cm 5th percentile female to 100 Kg/188cm 95th percentile male occupants). The evolution of this knee bolster assembly design is described using crush analysis, component testing to validate the crush analysis, instrument panel assembly level analysis with occupant models and sled tests. Steel and aluminum versions of this knee bolster are compared - in terms of weight, cost, design tunability for various crash conditions, structural stiffness etc.
2015-04-14
Technical Paper
2015-01-1457
Aditya Belwadi, Richard Hanna, Audrey Eagle, Daniel Martinez, Julie Kleinert, Eric Dahle
Abstract Automotive interior design optimization must balance the design of the vehicle seat and occupant space for safety, comfort and aesthetics with the accommodation of add-on restraint products such as child restraint systems (CRS). It is important to understand the range of CRS dimensions so that this balance can be successfully negotiated. CRS design is constantly changing. In particular, the introduction of side impact protection for CRS as well as emphasis on ease of CRS installation has likely changed key design points of many child restraints. This ever-changing target creates a challenge for vehicle manufacturers to assure their vehicle seats and occupant spaces are compatible with the range of CRS on the market. To date, there is no accepted method for quantifying the geometry of child seats such that new designs can be catalogued in a simple, straightforward way.
2015-04-14
Technical Paper
2015-01-1455
Kenshi Torikai, Hitoshi Higuchi, Kazuhiro Seki
Abstract The reaction force of a traditional passenger airbag tends to reduce after the initial inflation and before contact with the occupant, since the vent structure discharging the internal gas is always open. A potential means to prevent this drop in the airbag reaction force includes the addition of a variable vent structure which keeps the vent hole closed until occupant contact to maintain the airbag internal pressure and then opens to vent gas after the contact. However, variable vent structures may involve issues from a complicated structure due to additional parts in its construction. The goal of this study was to develop a simplified variable vent structure. A slit-type vent structure was investigated. This structure incorporates no additional parts to a conventional airbag with a hole-type vent. Static deployment tests and impactor tests were conducted to measure the effect of the slit-type vent structure and to compare it with the conventional airbag.
2015-04-14
Technical Paper
2015-01-1453
Jingwen Hu, Kurt Fischer, Paul Lange, Angelo Adler
Abstract In this study, two sled series were conducted with a sled buck representing a compact vehicle. The first series of tests focused on the effects of crash pulse, impact angle, occupant size, and front seat location on rear seat occupant restraint with a generic rear-seat belt system without pre-tensioner or load limiter. The second series of tests focused on investigating the benefit of using advanced features for rear-seat occupant restraint in the most severe crash condition in the first sled series. The first series of tests include 16 test conditions with two impact angles (0° and 15°), two sled pulse (soft and severe), and four ATD sizes (HIII 6YO, HIII 5th female, HIII 95th male, and THOR-NT) with two ATDs in each test. The driver seat was located at the mid position, while the front passenger seat was positioned such that a constant distance between the ATD knee and the front seat is achieved.
2015-04-14
Technical Paper
2015-01-1460
Massoud Tavakoli, Janet Brelin-Fornari
Abstract This study was conducted to explore the effect of various combinations of seatbelt-related safety components (namely, retractor pretensioners and load limiting retractors) on the adult rear passenger involved in a frontal collision. The study was conducted on a 50th Male and a 5th Female Hybrid III ATD in the rear seat of a mid-sized sedan. Each ATD was seated in an outboard position with 3-point continuous lap-shoulder belts. On these belts were combinations of pretensioners and load limiters. Since the main objective of this test series was to cross-compare the seatbelt configurations, front seats were not included in the buck in order to avoid uncontrollable variables that would have affected the comparison study if the possibility of contact with the front seat were allowed. Nevertheless, there was a short barrier devised to act as a foot-stop for both ATDs.
2015-04-14
Technical Paper
2015-01-1458
Jia Hu
Abstract A Finite Element (FE) model for analysis of the rear row occupant injury assessment parameters in a frontal crash test was developed by using the LSTC Hybrid III 5th percentile FE dummy model. Three cases were studied using three different rear seatbelt retractor configurations, which were as follows: an ordinary retractor without load limiter or pretensioner (Case 1), a retractor with load limiter only (Case 2), and a retractor with load limiter and pretensioner (Case 3). The simulation results of each of these three cases were compared respectively to the results obtained from two frontal 50-kph full rigid barrier impact tests and one sled test. It turned out that the dummy kinematics and injury assessment parameters of the head, neck, chest, pelvis and femurs were all similar between test and simulation in the three cases. Thus, FE simulation models can be used to predict dummy injury assessment parameters.
2015-04-14
Technical Paper
2015-01-1466
Dietmar Otte, Thorsten Facius, Birgit Wiese
Abstract The overall number of severely injured participants and fatalities in road traffic accidents has decreased enormously during the last decades especially in Europe, but casualties in the group of riders of motorcycles have only decreased in a smaller percentage. In countries of Asia the numbers of motorcycle casualties are increasing regarding the popularity of motorcycle riding. The aim of this study is to analyze the current accident situation of motorcycles in Germany with severely injured and killed riders of motorcycles with cubic capacity > 125 cm3 in Germany, to identify the characteristics in injury mechanisms and accident constellations to find countermeasures to be suggested for worldwide accident avoidance and injury reduction. The study was carried out on the basis of accident data of 1,493 drivers of motorcycles involved in traffic accidents in Germany.
2015-04-14
Technical Paper
2015-01-1465
Sho Nikaido, Shota Wada, Yasuhiro Matsui, Shoko Oikawa, Toshiya Hirose
Abstract Although traffic accidents in Japan involving bicycles have been decreasing yearly, more than 120,000 per year still occur. Few data exist regarding the mechanisms underlying bicycle accidents occurring at intersections. Such dangerous situations form the backdrop of the warning and automatic braking systems being developed for motor vehicles. By clarifying cyclist behavioral characteristics at crucial times, it may be possible to introduce a similar warning system for cyclists as a countermeasure to reduce accidents. The objective of this study is to clarify the mechanism of accidents involving bicycles and to obtain useful data for the development of a warning system for cyclists. A video camera and software investigated and analyzed cyclists' speed and trajectory at an intersection where many accidents occur. Cyclists entering the intersection from one direction were recorded.
2015-04-14
Technical Paper
2015-01-1462
Seung Jun Yang
Abstract Each year, more than 270,000 pedestrians lose their lives on the world's roads. Globally, pedestrians constitute 22% of all road traffic fatalities, and in some countries this proportion is as high as two thirds of all road traffic deaths. Millions of pedestrians are non-fatally injured and some of whom are left with permanent disabilities. These incidents cause much suffering and grief as well as economic hardship. To lower the rate of pedestrian injuries and fatalities, the Euro-Ncap committee adopted an overall impact star-grade system in 2009, making the pedestrian protection cut-off score required to obtain the best impact-star grade more stringent until 2016. It is very difficult to surpass the enhanced pedestrian cut-off score using past methods. In this paper, I determine the hood's worst-performing areas in terms of pedestrian protection by analyzing previous pedestrian test results.
2015-04-14
Technical Paper
2015-01-1471
Hiroyuki Asanuma, Yukou Takahashi
Abstract The evaluation of pedestrian safety performance of vehicles required by regulations and new car assessment programs (NCAPs) have been conducted. However, the behavior of a pedestrian in an actual car-pedestrian accident is complex. In order to investigate injuries to the pedestrian lower body, the biofidelity of the lower limb and the pelvis of a pedestrian dummy called the POLAR II had been improved in past studies to develop a prototype of the next generation dummy called the POLAR III. The biofidelity of the thigh and the leg of the POLAR III prototype has been evaluated by means of 3-point bending. However, the inertial properties of these parts still needed to be adjusted to match those of a human. The biofidelity of the pelvis of the POLAR III prototype has been evaluated in lateral compression. Although the experiment using PMHSs (Post Mortem Human Subjects) was conducted in dynamic condition, the dummy tests were performed only in quasi-static condition.
2015-04-14
Journal Article
2015-01-1470
Takahiro Isshiki, Atsuhiro Konosu, Yukou Takahashi
Abstract Current legform impact test methods using the FlexPLI have been developed to protect pedestrians from lower limb injuries in collisions with low-bumper vehicles. For this type of vehicles, the influence of the upper body on the bending load generated in the lower limb is compensated by setting the impact height of the FlexPLI 50 mm above that of pedestrians. However, neither the effectiveness of the compensation method of the FlexPLI nor the influence of the upper body on the bending load generated in the lower limb of a pedestrian has been clarified with high-bumper vehicles. In this study, therefore, two computer simulation analyses were conducted in order to analyze: (1) The influence of the upper body on the bending load generated in the lower limb of a pedestrian when impacted by high-bumper vehicles and (2) The effectiveness of the compensation method for the lack of the upper body by increasing impact height of the FlexPLI for high-bumper vehicles.
2015-04-14
Technical Paper
2015-01-1469
Yan Wang, Taewung Kim, Yibing Li, Jeff Crandall
Abstract Multibody human models are widely used to investigate responses of human during an automotive crash. This study aimed to validate a commercially available multibody human body model against response corridors from volunteer tests conducted by Naval BioDynamics Laboratory (NBDL). The neck model consisted of seven vertebral bodies, and two adjacent bodies were connected by three orthogonal linear springs and dampers and three orthogonal rotational springs and dampers. The stiffness and damping characteristics were scaled up or down to improve the biofidelity of the neck model against NBDL volunteer test data because those characteristics were encrypted due to confidentiality. First, sensitivity analysis was performed to find influential scaling factors among the entire set using a design of experiment.
2015-04-14
Technical Paper
2015-01-1467
Chinmoy Pal, Tomosaburo Okabe, Kulothungan Vimalathithan, Jeyabharath Manoharan, Munenori Shinada
Abstract Logistic regression analysis for accident cases of NASS-PCDS (National Automotive Sampling System-Pedestrian Crash Data Study) clearly shows that the extent and the degree of pedestrian's lower extremity injury depend on various factors such as the impact speed, the ratio of the pedestrian height to that of the bonnet leading edge (BLE) of the striking vehicle, bumper to knee ratio, bumper lead angle, age of the pedestrian, and posture of the pedestrian at the time of impact. The pedestrian population is divided in 3 groups, equivalent to small-shorter, medium-height and large-taller pedestrian with respect to the “pedestrian to BLE height-ratio” in order to quantify the degree of influence of lower leg injuries in each group. Large adult male finite element model (95th percentile male: 190 cm and 103 kg) was developed by morphing the Japan Automobile Manufacturers Association (JAMA) 50th percentile male.
2015-04-14
Technical Paper
2015-01-1217
Changhong Liu, Lin Liu
Abstract Many problems are associated with the large battery operation current, such as battery overheating, lithium plating, and mechanical structural instability of battery materials. All these problems may cause battery safety issues in fuel cell hybrid vehicles (FCHVs), e.g., battery explosions and thermal runaway have been reported and may cause public anxiety about FCHVs. Previous researches on FCHV power management strategy have focused on minimizing fuel consumption. But more attention needs to put on the battery current constraint for analysis of battery state of charge (SOC) and battery state of health (SOH). This research targets optimizing the FCHV battery pack operation within a safe current range through power management strategy to increase the safety of the battery pack while improving battery usage via SOC control. Battery SOH is also evaluated in the study.
2015-04-14
Technical Paper
2015-01-1341
Hisaki Sugaya, Yoshiyuki Tosa, Kazuo Imura, Hiroyuki Mae
Abstract The explicit methods analysis solver LS-DYNA was used to create technology for simulating airbag deployment and plastic airbag lid tear-away in the front passenger seat. The present study clarified the mechanical properties and the transitions in fracture pattern of the material at low temperature plastic this way, an appropriate modeling method was developed and the prediction accuracy of the simulation of airbag lid tear-away on deployment was increased. Tensile testing of the material was carried out where there were differences in thickness of the tear-away section and the fracture characteristics were determined. A material model was created by analyzing changes in fracture characteristics and collapse patterns, taking into consideration the effects of strain and strain rate localization on fracture strain as well as ductile-brittle fracture transition. Next, airbags were subjected to the impactor testing.
2015-04-14
Technical Paper
2015-01-1369
Kai Liu, Andres Tovar, Emily Nutwell, Duane Detwiler
Abstract This work introduces a new design algorithm to optimize progressively folding thin-walled structures and in order to improve automotive crashworthiness. The proposed design algorithm is composed of three stages: conceptual thickness distribution, design parameterization, and multi-objective design optimization. The conceptual thickness distribution stage generates an innovative design using a novel one-iteration compliant mechanism approach that triggers progressive folding even on irregular structures under oblique impact. The design parameterization stage optimally segments the conceptual design into a reduced number of clusters using a machine learning K-means algorithm. Finally, the multi-objective design optimization stage finds non-dominated designs of maximum specific energy absorption and minimum peak crushing force.
2015-04-14
Technical Paper
2015-01-1364
Tao Wang, LIangmo Wang, Yuanlong Wang, Xiaojun Zou, Fuxiang Guo
Abstract The design of aluminum foam reinforced thin-walled tubes has garnered much interest recently due to the high energy absorption capacity of these tubes. As a new kind of engineering composite material, aluminum foam can hugely increase the crashworthiness capacity without sacrificing too much weight. In this paper, axisymmetric thin-walled hollow tubes with four different kinds of cross-sections (circular, square, hexagonal and octagonal) are studied to assess their performance for crashworthiness problems. It is found that the tube with square cross-section has the best crashworthiness performance under axial impact. To seek optimal designs of square aluminum foam reinforced thin-walled tubes, a surrogate modeling technique coupled with a multi-criteria particle swarm optimization algorithm has been developed, to maximize specific energy absorption (SEA) and minimize peak crash force (PCF).
2015-04-14
Technical Paper
2015-01-1362
Chao Li, Il Yong Kim
Abstract A bumper system plays a significant role in absorbing impact energy and buffering the impact force. Important performance measures of an automotive bumper system include the maximum intrusions, the maximum absorbed energy, and the peak impact force. Finite element analysis (FEA) of crashworthiness involve geometry-nonlinearity, material-nonlinearity, and contact-nonlinearity. The computational cost would be prohibitively expensive if structural optimization directly perform on these highly nonlinear FE models. Solving crashworthiness optimization problems based on a surrogate model would be a cost-effective way. This paper presents a design optimization of an automotive rear bumper system based on the test scenarios from the Research Council for Automobile Repairs (RCAR) of Europe. Three different mainstream surrogate models, Response Surface Method (RSM), Kriging method, and Artificial Neural Network (ANN) method were compared.
2015-04-14
Technical Paper
2015-01-1387
Richard Young
Abstract This study revises the odds ratios (ORs) of secondary tasks estimated by Virginia Tech Transportation Institute (VTTI), who conducted the 100-Car naturalistic driving study. An independent and objective re-counting and re-analysis of all secondary tasks observed in the 100-Car databases removed misclassification errors and epidemiological biases. The corrected estimates of secondary task crude OR and Population Attributable Risk Percent (PAR%) for crashes and near-crashes vs. a random baseline were substantially lower for almost every secondary task, compared to the VTTI estimates previously reported. These corrected estimates were then adjusted for confounding from demographics, time of day, weekday-weekend, and closeness to junction by employing secondary task counts from a matched baseline from a later VTTI 100-Car analysis. This matched baseline caused most OR estimates to decline even further.
2015-04-14
Technical Paper
2015-01-0136
Ying Fan
Abstract In order to overcome the drawback that the traditional risk priority number method could not clearly make a risk priority sequence, a new analysis method of RPN was presented. Combined with loss costs, this method was based on FMEA. Several quantitative parameters such as servicing time and costs were introduced to replace the three parameters used in the traditional method. And it took loss costs caused by failure as the final risk priority number, instead of severity of effects, probability occurrence and difficulty detection. Finally, safety evaluation to work equipment and other critical systems of a forklift was processed as a case to illustrate this proposed method. The results showed that the results processed by the new method could be utilized to solve the problem that the RPN values couldn't be sorted.
2015-04-14
Technical Paper
2015-01-1434
Gary A. Davis
Abstract Martinez and Schlueter [6] described a three-phase model for reconstructing tripped rollover crashes, where the vehicle's path is divided into pre-trip, trip, and post-trip phases. Brach and Brach [9] also described this model and noted that the trajectory segmentation method for the pre-trip phase needed further validation. When a vehicle leaves a measurable yaw mark at the start of its pre-trip phase it might be possible to compare estimates from the three-phase model to those obtained using the critical speed method, and this paper describes Bayesian reconstruction of two such cases. For the first, the 95 percent confidence interval for the case vehicle's initial speed, estimated using the critical speed method, was (64 mph, 81 mph) while the 95 percent confidence interval via the three-phase model was (66 mph, 79 mph).
2015-04-14
Technical Paper
2015-01-1484
Daniel E. Toomey, Eric S. Winkel, Ram Krishnaswami
Abstract Since their inception, the design of airbag sensing systems has continued to evolve. The evolution of air bag sensing system design has been rapid. Electromechanical sensors used in earlier front air bag applications have been replaced by multi-point electronic sensors used to discriminate collision mechanics for potential air bag deployment in front, side and rollover accidents. In addition to multipoint electronic sensors, advanced air bag systems incorporate a variety of state sensors such as seat belt use status, seat track location, and occupant size classification that are taken into consideration by air bag system algorithms and occupant protection deployment strategies. Electronic sensing systems have allowed for the advent of event data recorders (EDRs), which over the past decade, have provided increasingly more information related to air bag deployment events in the field.
2015-04-14
Technical Paper
2015-01-1756
Daniel E. Toomey, Debora R. Marth, William G. Ballard, Jamel E. Belwafa, Roger Burnett, Robert W. McCoy
Abstract For more than 30 years, field research and laboratory testing have consistently demonstrated that properly wearing a seat belt dramatically reduces the risk of occupant death or serious injury in motor vehicle crashes. In severe rollover crashes, deformation to vehicle body structures can relocate body-mounted seat belt anchors altering seat belt geometry. In particular, roof pillar mounted shoulder belt anchors (“D-rings”) are subject to vertical and lateral deformation in the vehicle coordinate system. The ROllover Component test System (ROCS) test device was utilized to evaluate seat belt system performance in simulated severe rollover roof-to-ground impacts. A mechanical actuator was designed to dynamically relocate the D-ring assembly during a roof-to-ground impact event in an otherwise rigid test vehicle fixture. Anthropomorphic test device (ATD) kinematics and kinetics and seat belt tensions were compared between tests with and without D-ring relocation.
2015-04-14
WIP Standard
J2938
This SAE Recommended Practice provides test procedures, requirements, and guidelines for the methods of the measurement of lumen maintenance of LED devices (packages, arrays and modules). This document does not provide guidance or make any recommendation regarding predictive estimations or extrapolation for lumen maintenance beyond the limits of the lumen maintenance determined from actual measurements.
2015-04-14
Technical Paper
2015-01-0493
Ying Wang, Ye Wang, You Qu, Sumin Zhang, Weiwen Deng
Abstract Vision-based Advanced Driver Assistance Systems has achieved rapid growth in recent years. Since vehicle field testing under various driving scenarios can be costly, tedious, unrepeatable, and often dangerous, simulation has thus become an effective means that reduces or partially replaces the conventional field testing in the early development stage. However, most of the commercial tools are lack of elaborate lens/sensor models for the vehicle mounted cameras. This paper presents the system-based camera modeling method integrated virtual environment for vision-based ADAS design, development and testing. We present how to simulate two types of cameras with virtual 3D models and graphic render: Pinhole camera and Fisheye camera. We also give out an application named Envelope based on pinhole camera model which refers to the coverage of Field-of-Views (FOVs) of one or more cameras projected to a specific plane.
2015-04-14
Technical Paper
2015-01-1417
Jeffrey Muttart
Abstract Controlled studies identified several factors that influence drivers' swerving when responding to in an emergency situation. Specifically, driver age, time-to-contact, amplitude of the steering action (steer within lane or swerving into the next lane), distraction, fatigue, natural lighting and available buffer space were identified as factors that influence steering behaviors. The goal of the current research was to identify the extent to which each factor changed swerving performances of drivers who were faced with a crash or near crash. Results from crashes and near crashes were obtained from the InSight (SHRP-2) naturalistic driving study. The results from the controlled studies and the results from the naturalistic driving research were consistent in many ways. Drivers engaged in a visual-manual secondary task were much younger than were the drivers who had no distracting secondary task.
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